Paterson D H, Cunningham D A
Eur J Appl Physiol Occup Physiol. 1976 Aug 12;35(3):223-30. doi: 10.1007/BF02336196.
A comparison was made of methods used to calculate cardiac output by the indirect (CO2) Fick procedure (equilibrium method). Alternative methods for calculation of arterial PCO2, mixed venous PCO2, and conversion of gas tension to content were tested. Cardiac output values determined with a "corrected" equilibrium PCO2, to approximate mixed venous PCO2, were observed to be closest to cardiac output values determined on similar populations by the dye dilution method. Arterial PCO2 was best estimated from the Bohr equation using a dead space in exercise from prediction equations in the literature applicable to the populations under study. CO2 dissociation curves used to derive the veno-arterial CO2 content difference, were shown to differ considerably. For the present, the curve by McHardy [25], as modified by Jones (personal communication), and similar to the standard Comroe curve [5], was chosen.
对通过间接（二氧化碳）菲克法（平衡法）计算心输出量所使用的方法进行了比较。测试了计算动脉血二氧化碳分压、混合静脉血二氧化碳分压以及将气体分压转换为含量的替代方法。观察到，使用“校正”后的平衡二氧化碳分压来近似混合静脉血二氧化碳分压所确定的心输出量值，与通过染料稀释法在相似人群中确定的心输出量值最为接近。动脉血二氧化碳分压最好根据玻尔方程，利用文献中适用于所研究人群的预测方程来估算运动时的死腔。用于推导静脉 - 动脉二氧化碳含量差的二氧化碳解离曲线显示出相当大的差异。目前，选择了由琼斯（个人交流）修改的麦克哈迪[25]曲线，该曲线与标准康罗伊曲线[5]相似。
